Safety device for elevators



(No Model.) 2 Sheets-Sheet 1.

F. H. SHURTZ 8: H. G. SWAN.

SAFETY DEVICE FOR ELEVATORS. No. 504,629. Patented Sept. 5, 189,3.

WITNESSES: INVENTOHS W wwmi) B)" mm o ATTORNEYS.

(No Model.) 2 Sheets-Sheet 2.

F. H. SHURTZ.& H. G. SWAN.

SAFETY DEVICE 0R ELEVATORS. No. 504,629. Patented Sept. 5, 1893.

WITNESSES: J [12% d. By flmg v AZTOHNEYS.

and adjacent parts.

UNITED STATES PATENT OFFICE.

FRANK HARRY SHURTZ AND HENRY GEORGE SW'AN, OF SAN FRANCISCO, CALIFORNIA.

SAFETY DEVICE FOR ELEVATORS.

SPECIFICATION formingpart of Letters Patent No. 504,629, dated September5, 1893.

Application filed September 13, 1892- Serial No. 445| (N0 1110581) Toall whom it may concern:

Be it known that we, FRANK HARRY SHUETZ and HENRY GEORGE SWAN, of SanFrancisco, in the county of San Francisco and State of Oalifornia,havein vented a new and Improved Safety Device for Elevators, of which thefollowing is a full, clear, and exact description.

The object of the invention is to provide a new and improved safetydevice for elevators, which is simple and durable in construction, veryeffective and automatic in operation, and arranged in such a manner thatin case of accident the cage is instantly locked in place, and isadapted to be readily unlocked as soon as the rope is again attached tothe cage and the latter lifted.

The invention consists of certain parts and details and combinations ofthe same, as will be fully described hereinafterand then pointed out inthe claims.

Reference is to be had to the accompanying drawings forming a part ofthis specification, in which similar letters of reference indicatecorresponding parts in all the figures.

Figure 1 is a sectional side elevation of the improvement on the line 11in Fig. 3. Fig. 2 is a transverse section of the cable pulley Fig. 3 isa plan view of the improvement with parts in section and parts brokenout; and Fig. 4 is a transverse section of one of the guides and theblocks therein.

The elevator is provided with the usual cage A, hung on the cable orrope B, passing over the usual pulley C, journaled on the frame D, onthe top of the elevator shaft, as is plainly shown in the drawings. Thecable, after leaving the pulley G, passes over a second pulley C", andthen to the hoisting device which imparts the necessary movement to thecable to cause the cage to ascend and descend in the elevator shaft inthe usual manner.

On the opposite sides of the cage A and ranging from top to bottom arearranged lugs E, which extend into the guides F, arranged vertically inthe elevator shaft and constructed of a metallic back plate F, on whichare riveted angle irons F and F forming a passage or guideway for thelugs E of the cage A. It will be understood that although but two ofsaid logs are shown on each side of the cage, any desired and necessarynumber of the same may be employed.

In the guideway of each guide F are pivoted blocks G, preferably madeLshape, and having their pivots H, held in the side plates F and F ofthe guides F. The arms G and G2 of each block G are arranged in such amanner that when the said blocks are in the position shown in Fig. 1,they are not touched by the lugs E on the ascent and descent of the cageA. \Vhen, however, a swinging motion is given to the blocks the sameswing into the position shown in dotted lines in Fig. 1, so that the armG2 rests against the back plate F of the guide F and the other arm Gextends horizontally and into the path of the lugs E. The blocks G arelocated one above the other throughout the entire height of each guideand each block has formed therein a notch G adapted to be entered by thecross bolts of the links of a chain 1, extending in the guideways of theguides F and having its upper link I, supported on a bolt J, mounted toslide longitudinally in a suitable bearing K, the outer end of the boltbeing additionally supported in a lug K, extending from the bearing K.The bolt J is held in an outermost position by a spring K to preventaccidental shifting of the bolt and consequent displacement of the link.

The inner end of each bolt J is connected by a rope or chain L, with abell crank lever N, fulcrumed on the under side of the frame D, the saidbell crank lever being also connected with a rope or chain 0, attachedto a forked arm P, engaging the shaft (J of the pulley O, as is plainlyillustrated in Fig. 2. The shaft 0 is journaled in bearings 0 mounted toslide vertically in guideways D, arranged on the frame D, the saidbearings being supported on springs 0 hen the elevator is in runningorder, the blocks G are in the position illustrated in the drawings, soas to be out of the path of the lugs E; now, in case the ropeor cable B.breaks, the pulley O is relieved of the weight of the cage A and thesprings 0* will consequently move the bearings 0 the shaft 0 and pulleyC, upward, whereby the forked armP is moved in a like direction and bythe ropes or chains 0 imparts a swinging motion to the bell crank leversN which in turn, pull on the ropes or chains L, so that the bolts J arecaused to slide inward and disengage the links I of the chains I in thetwo guides F. The chains I thus drop, and in doing so the cross bolts ofthe links of the chains pass out of the notches in the blocks G so thatthe arms G of the latter swing into the position shown in dotted linesin Fig. 1 and above described. As the arms G of the blocks G now extendinto the path of the lugs E, a downward n10- tion of the cage A will beprevented as the lugs will seat themselves on the two next blocks G oneach side of the elevator cage A. The cable 13, after being repaired andattached to the cage A, is caused to travel so as to lift the cage A toraise the lugs E above and out of the way of the respective blocks G,and the operator then pulls the chain I upward by hand so as to againengage the upper links I with the bolts J, the latter being free toslide outward on the downward movement of the pulley O in its bearings.At the same time, the cross bolts of the links of the chains enter thenotches in the blocks G, causing said blocks to swing out of the path ofthe lugs E in to the position shown in full lines in Fig. 1. It isunderstood that when the cage A is again lifted by the cable B, apressure is exerted on the pulley C so that the shaft 0 of the latterand its bearings (3 move downward and compress the springs 0 and at thesame time a downward movement is given to the forked arm P to releasethe bolts J. The latter move out in their normal positions by the actionof the springs K held on the said bolts.

It will be seen that this device is very simple and durable inconstruction, and permits of a ready adjustment and resetting in case ofaccident, no mechanic being required for resetting the blocks nor is itnecessary to stop the elevator for days in order to repair the damageusually done by clutches digging into the wooden guides of the elevatorshaft.

By constructing the guides as shown and described, it is impossible forthem to spread when the cage stops between the doors.

Having thus described our invention, we claim as new and desire tosecure by Letters Patent-- 1. A safety device for elevators, comprisinga. bolt adapted to be actuated from the cable pulley, a chain adapted tobe supported on the said bolt, and a series of pivoted blocks connectedwith each other by the said chain, and adapted to swing into the path ofthe cage to stop the descent of the latter, substantially as shown anddescribed.

2. Asafety device for elevators, comprising a bolt adapted to beactuated from the cable pulley, a chain adapted to be supported on thesaid bolt, a series of pivoted blocks connected with each other by thesaid chain and adapted to swing into the path of the cage to stop thedescent of the latter, and intermediate mechanism, substantially asdescribed, for connecting the said bolt with the cable pulley, as setforth.

3. A safety device for elevators, comprising an arm hung on the shaft ofthe cable pulley, a bolt mounted to slide, an intermediate mechanism forconnecting the said bolt with the said arm, a chain supported on thesaid bolt, and'a series of pivoted blocks adapted to be engaged by thesaid chain, the said blocks being adapted to swing into the path of theelevator cage, to stop the descent of the latter whenever the said boltis withdrawn and the chain released, substantially as shown anddescribed.

4. In a safety device for elevators, the combination with a cageprovided with lugs, a cable for supporting the cage, and a cable pulleyjournaled in spring-pressed bearings, of a series of blocks mounted toswing and located one above the other, a chain for connecting the blockswith each other, a bolt for supporting the said chain, and anintermediate mechanism for connecting the said bolt with the said cablepulley, to withdraw the said bolt whenever the pulley slides inward,substantially as shown and described.

5. In a safety device for elevators, the combination with a cageprovided with lugs, and a guide arranged in the elevator shaft and intowhich the lugs on the cage project, of angular blocks pivoted in theguide, a chain with which the blocks are connected a support for thechain, and means for releasing the said support from the chain to allowthe blocks to drop into the path of the lugs on the cage, substantiallyas described.

6. In a safety attachment for elevators the combination with a cageprovided with lugs, and a guide arranged in the elevator shaft and intowhich the lugs on the case project, of angular blocks pivoted in theguide, a chain with which the blocks engage, a spring pressed bolt forsupporting the chain, and means for releasing the bolt from the chain toallow the blocks to drop into the path of the lugs of the cage,substantially as herein shown and described.

FRANK HARRY SHURTZ. HENRY GEORGE SWAN. Witnesses:

ALEX. L. LYNN, L. PH. BOLANDER.

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